Record and the manufacture thereof for talking machines



Patented is. 11, 1927' UNITED STATES- PATENT OFFICE.

FREDERICK JOHN TURNER AND JOHN EDWARD ERNEST STARCK, F ELSTREE, ENG- LAND, ASS IGNORS 0F ONE-FOURTH TO JOHN RICHARDSON CRAIG, OF LONDON, ENG- LAND, AND ONE-FOURTH "T0 ENGLAND. i

PERCIVAL JAMES PACKMAN, OE HIGHBURY, LONDON,

RECORD AND THE MANUFACTURE THEREOF FOR TAiLKING MACHINES.

No Drawing. Application filed June 7, 1924. Serial No. 718,673, and in Great Britain June 19, 1923.

This invention relates to sound records 7 for talking machines of the type wherein matrix and a body portion formed of a plurality of sheets of paper alternating with layers of plastic composition placed on the back of the record surface sheet, the body sheets being prepared in substantiallytlie same manner as the record surface sheet,

using .a cheap or inferior composition instead of the expensive shellac composition. The several prepared sheets were then united by heat and pressure.

The object of the present invention is to provide a durable record which, while capable of manufacture at a low cost, posesses an improved sound-recording surface which renders reproduction of the recorded matter more faithfully, with better tone and with the accompaniment of less extraneous noise or scratching sound.

By aid of the invention the manufacture and production of records is considerably simplified and thin and comparatively flexible records may be produced with attendant advantages as regards weight, 'space occupied and liability to damage.

has been found necessary to employ a record surface material in preformed thin sheet form having the qualities and mechanical or physical characteristics exemplified by a non-inflammable and non-resinous cellu:

" losic material, such as cellulose acetate,

which may be heated to relatively high temperature without risk of material chemical change and according to this invention materials .of theform and nature above specified are essentially employed.

The adhesive or binding material em ployed in producing a record according-to the invention may be the same in bas s as that of the record surface in an appropriate state for the purpose in view, or such may be of/a different or cheaper material providing such possessessubstantially similar mechanical or physical characteristics.

It is to be understood that the material employed is used as'an adhesive or binder as distinct from a filling agent or material intended to increase or form a substantial part of the thickness oftlie record.

Record surface material in preformed thin sheets of the kind above referred to as, for,

example,'cellulose acetate, is known for the production of sound records for talking machines and various proposals have, from time to time, been made in respect to the mounting of such upon a body or support such as a sheet of paper, cardboard, plywood or other fibrous material, or upon a coinparatively thick preformed base of asphaltic nature with or without a layer of paper or cardboard incorporated in-the mass and with a sheet of paper interposed between the mass or base to prevent the latter from dis turbing the record surface during the impression process and as a uniting wafer or agent.

It has also been proposed toe'mploy anadhesive or binding material of a similar with more or less success but do not pro- Inorder to secure the desiredresults 1i] duce 'a record ofthe quality or nature of that achieved by the present invention, according to which the laminated body or'siipport is formed of a plurality of sheets of a porous and absorbent paper, such as blotting paper, united together by a binding material of the nature. specified, permeating the sheets throughout so that the laminations are formed into a practically integral body with a record surface material of the nature and in the form specified above a'p plied thereto. v

The invention consists in a method. of

making a sound record of the type described consisting in treating a plurality of sheets of a porous and absorbent paper with binding material of-the kind described'so that they may be thinly cemented together, providing a sheet or sheets of recording surface'material of the form and nature specified, assembling said paper and record surface sheets and impressing a matrix (or matrices) upon the record sheet (or sheets) under pressure and at a temperature adapted to incorporate or amalgamate the Whole as a practically integral body.

The invention also comprises a method of manufacturing sound records of' the type described consisting in providingrecord surplurality of coated sheets of paper between two outer'sheets of record surface material face material of the nature and form specified, providing a plurality of sheets of porous and absorbent paper with a thin coat or layer of binding material so as to leave a porous layer beneath the coating, including a and impressing a matrix (or matrices) thereon at atemperature adapted to drive outthe volatile constituent of the r materials employed andto cause the binding material to unite the sheets together and thoroughly to impregnate each. paper sheet so that a practically iiitegral record is formed with binding material permeating the whole body.

The invention further comprises a method of manufacturing sound records of the type described consisti g in preparing a laminated body treated with binding material of. the kind described, placing such body between record surface sheets of the nature and form specified and impressing a matrix upon the record surface material at a temperature of the order of 290 F .In referring to record surface material or-surface sheets it is to be understood that such terms include a record surface sheet in which the sound record is formed for eachside of a record,- or in the case of so-.- called single-sided records a backing sheet h should'be of substantially the same thick ness and general nature" as a sheet intended to receive a record groove although such may be of a cheaper material or make.

The material generally known as noninflammable celluloid has-been found suitable bothas a base forthe adhesive or binding materiaLand for the recording surface sheet (or sheets). .This material is known as a commodity in sheet form and sheets of an appropriate thickness. such as 5/1000ths of an inch, are procurable and may be appropriately emp dyed and treated according to the invention; i

Alternatiyely, a very similar raw material may be manufactured asfollows :200 parts of cotton cellulose (about 5 per cent. moist) is treated with a mixture of 800 parts of dride, this being added progressively while agitating the solution at atmospheric tem perature say 62 F. As soon as the solution is complete water is run in while still agitating. The thin precipitate (cellulose acetate) is washed and pressed and can be.

moulded or set into blocks and when sufli ciently seasoned sheets down to 5/1000ths of an inch in thickness can be cut therefrom.

Any appropriate colouring matter may be added to the solution of cellulose acetate, such as could be dissolved or suspended in the solution or solvents.

By moulding the cellulose acetate in a special manner sheets of, say, 3/l000ths of an inch may be prepared. Sheets of this fineness may be produced'by moulding the cellulose acetate in cylindrical moulds. of

slightly larger diameter than that ofthe disc records to be made. The moulding of the material in cylinders of comparatively small diameters makes it possible to operate there-' on by aid of a guillotine having a short stifi' knife to produce sheets or films of approximately 3/1000ths of an inch in thickness.

i It 'is preferred to incorporate the inner body with the recording surface material while imposing a sound record (that is to say, arecord groove or track) upon the recording surface material by the aid of a matrx under pressure, and such treatment should be carried outat a temperature such as will ensure the expulsion of the bulk of the solvents from the compositions employed and cause the recording surface material to become hardened and toughened after treat-' ment, while at the same time the coating of binding material is driven into porous sheets thoroughly to impregnate such.

. It is thought that the employment of laminated porous material for the innerbody' plays an important part in the. product-ion .of a satisfactory sound record as the porous layer under the binder coat or layer in the material permits, or provides a' path for, the escape of the solvent vgases and enables a high temperature (as, for example, in the neighbourhood of 290 F.) to be successfully employed.

\ In recording sound waves ithas been proposed-to reduce the depth and width'of the sound wave trackfor the purpose of lessening' the surface scrape' in reproduction.

Such expedients, however, have a tendency to reduce the volume of the sound. The use of the surface employed in the present in-' vention considerably reduces the surface scrape and it therefore becomes possible to, revert to deeper grooves ortracks. This might be accomplished bythe use of a thicker outer surface sheet of recording material but to obviate thus increasing the thickness (and quantity) of material to accommodate the required depth of groove or track, it has been found that if a sheet of recording surfacematerial, of say 3/1000ths of an inch thick, is employed in conjunction with a film or layer of india-rubber solution or other plastic body which is adapted to sheet, a deep sound wave grooveor track act as a.cushion and as an adhesive or hinder, interposed between the outer surface.

of the inner body andthe recording surface may be produced in the latter. The interposed cushion enables the thin recording surface sheet readily to be driven in the groove of the matrixin the process of pressing and hardening. as the cushion supports and backs up the sheet, ensuring a perfect impression contact. In some cases the cush- .ion may enable the track 'or'groove to be formed bydepressing the bottom thereof slightly out of, the plane of the surface sheet, that is to say so that the reverse of the sheet would disclose or show the impression or an indication of the sound groove or track.

In carrying the invention into effect according to one convenient mode byway of example,'paper pulp,hygroscopic but substantially free from extraneous or bituminous matter, is'made in wet or sheet formsuch being soft, absorbent and of a uniform thickness. These sheets, for example, should be in the neighbourhood of 17 x 22 and of a thickness that causes the sheets to weigh, say 27-30 lb. to the ream, but it is is possible to procure upon the market sheets preferred to employ rolls of web 10 or 12 wide of a corresponding thickness. \Vhile it is desirable to manufacture or have manufactured sheets of the above nature, it

of absorbent and porous paper in the nature of blotting paper which may be found to serve the required purpose if free from chemical, water-marking acid or other injurious matter.

The absorbent sheets may be cut to the desired shape in the first instance or the 1 coated sheets or a laminated body made of such sheets may be stamped.

The sheets are coated or partially impregnated on each-side with an adhesive or binding material so as-to have an inner layer which is porous and substantially free from the binding material which should be a solution in an organic solvent (such as amyl acetate or alcohol. benzine. or a mixture of the two or amyl acetate and chloroform), of cellulose acetate, either procured as a finished product or according to the method of manufacture above described.

The binding material should be of a consistency such aswill enable it to be conveniently spread or coated upon the sheets to provide a thin layer or film "of the binding material upon each side thereof. Alternately, the adhesive or binding material may be prepared 'in separatefilms by running or spreading a thinner solution upon a glass sheet, allowing it to set and stripping it from the glass in the formof a film or tissue suitable for inter-posing between the sheets of the inner body or between the inner body and the surface material.

The coated sheets are allowed to dry or season for not less than 10 minutes until a considerable portion of the solvent of the binding material has evaporated. When suitably dried a number" of the sheets according to the thickness it is desired the tween ,the matrices of any suitable known i kind for impressing a souhd wave groove or track. These are heated by any appropriate heatingmeans to a temperature' up to 290 F. The pressure at which the printing or pressing of the record is performed makes -it possible to print from alight shell matrix which need not be backed for strengthening purposes. A perfectly satisfactory record has been produced at an ultimate pressure so low as 250 lb. to the square'inch.

The solvent gases appear to be driven off as the pressure is gradually lncreased at or about and during the reduction of the temperature as aforesaid. For example, the press maybe closed on the backs of the matrices at about lb. to the squareinch and after an interval of, say,five seconds the:

pressure. isjgradually but rapidly increased to approximately 250 lb. This actionfob viates any possibility ofimprisoning any of the escaping vapours of the solvent so often occurring in the process of printing where a high pressure (usually uncontrollable) is necessary, such pressure frequently exceeding twelve thousand pounds to the square inch',-a pressure that does not conduce to the serviceable life of a matrix even if strengthened and supported. and temperature are maintained for a -period of, say, from, one to five minutes '(depending on the nature of the means for cooling the press) or for a suflicient duration to cause the solvents both in the binding ma-. terial and the recording surface sheets to be The pressure I driven off to an extent such that the surface material becomes hard and tough and rendered-suitable for sound reproduction under the action of a stylus.

It should be observed that it is not necessary to retain the matrices and the record in thepress'until they are quite cold. The matrices and the enclosed record may be removed together from-the press (at a temperature almo 'st too high to lift them by naked fingers) and then placed between two cold" plates, the matrices and contained record being thus very quickly cooled. When cold, the matrices can be easily and quickly separated .from the surface of the pressed record by the act of applyinga slight pressurd by hand. h L

It is thought that the temperature to which the recording body,-including' the surface sheets, is'subjected, which is such as to render plastic or almost liquefy the external element, fails to destroy the substiince of the fthe'record material between matrices, plainv surface elements are employed-for the press ing and heating process, the temperature:-

materials treated owing to escape of the solvent gasesthrough the porous strata provided by the laminated sheets of the inner body. pressure'treatment causes the record surfaces to bear a perfect replica of the matrices and a sound record is producedin whichthe surface is hardened and toughened to .a degree that 'renders it more or less wear-proof while at the same time being perfectly smooth arid free from scratchingnoise under the action of the stylus. 3 V

' According to a modification, itis possible to make record blanks according to the above process, in which case instead of pressing being maintained well below that specified when it is desired to produce the finished sound record. The blanks thus formed may be stored for future use.

may be-impressed by pressure and heat treatment between matrices when the tem perature. would be raised to the .neighbour- .hood of 290? In order satisfactorily to T impress a sound record upon such blanks it is necessary in order to achieve the best results to reheat them at a comparatively low temperature in an atmosphere of thesolvent vapours or otherwise, sub ect them to hot vapours of the solvent.

Where it is .required to produce a record with a sound impression upon one side .only

I 7 the laminated inner body may be provided form or after the pressing operation the backing may be coated or deposited therewith a recording surface sheet as'hereinbefore ,described and with a backing of the same or inferior material of suitable tension which may be applied either in sheet upon by any suitable known process...

The heat and comparatively low A sound record in preforme Thesound records made according to this invention may be finished off by perforating the centie of the-disc, trimming the peripheral edge and if-necessary, sealing such.

When employing surface sheets of, say, 3/l00 )ths of an inch in thickness the outer surface of the inner body is coated with a thin layer of rubber solution which may be applied by means of a brush or-a wad of cotton-wool or flannel or, if a very thin solution of rubber is employed, this may be run on to the outer surface of the inner body. The rubber solution may be such as is used for patching rubber tyres and if the marketed commodity is too thickit may be thinned with afewdrops of ben'zine or petrol.

The coating of rubber is allowed to dry until it becomes slightly tacky. When the inner body with the rubber coating is in a suitable state the thin sheet of recording surface material which may be prepared as hereinbefore described is placed over the I rubber coating and the matrix is applied according to the method detailed above.

The heat and pressure by aid of the rubber cushion causes the material of the thin sheet to, be driveninto the groove of the matrix, the heat and pressure more or less vulcanizing the rubber operating as a cement betweenf'the inner body and the recording surface material. Thus the surface sheet, the rubber cushion and the inner body are amalgamated. In the process ofheating and pressing the solvent of the rubber is expelled with the'volatile gases mm the sur-' face material and theadhesive or binding material of the inner body.

When employing the rubber cushionit is.

found possible to dispense with the adhesive orbinding material between the recording surface material and the adjacent surface of the porous inner body. When employing the surface material in thethinner sheet form indicated, the paper or material used for the inner-body may be of a somewhat lighter nature,'that is to say sheets of the weight of27 lb. to the ream may be advantageously employed. c

Having now-described our invention, what we claim as new and desire to secure by Letters Patent is sembled and. which havebeen' heat treated plurality of sheets of under pressure between matrices at a tem- 4 perature'adapted to cause the adhesive and binding material the Sh ets together 7 and thoroughly to impregnate-each porous and absorbent sheet SO hat a practically ,integral record is formed witl'r the binding material permeating the whole body.

2. A flexible sound record for talking machines comprising, a record surface inpreformed thin sheet form of a non-inflammable and non-resinous cellulosic material and a laminated body portion on which the record surface is mounted consisting of a plurality of sheets of porous andabsorbent paperwhich have been coated with an adhesive and binder comprising a solution of noninflannnable and non-resinous cellulosic ma-' terial and heat treated at a temperature such'as to drive the adhesive and binden through the absorbent and porous sheets so that it inte rally incorporates and amalgamates the w ole.

3. A method of making a flexible sound record consistingv in providing" preformed thin sheets of'rec'ord surface material of a kind which is flexible, non-inflammable and non-resinous, providing a plurality of sheets of porous and absorbent paper for forming a laminated inner body, thinly coating each of the porous and absorbent sheets with an adhesive and binding material comprising a solution of a non-inflammable non-resinous material which remains flexible when dry, including the assembled coated sheets between two record surface sheets and impress.-

.ing matrices thereon at .a temperature adapted to cause the adhesive and binding material to unite the coated sheets together and thoroughly to impregnate each sheet so that a practically integral record is formed with the adhesive and binding material permeating the Whole body,

4. A method of making sound records for I talking machines consisting in employinga record surface ofthin sheets of non-inflammable and non-resinous cellulosic material, forming a laminatedi'nner body of a plurality of sheets of porous and absorbent paper thinly coated with an adhesive and binder comprising a solution'of a non-inflammable and non-resinous cellulosic material and heat treating vthe assembled sheets-under pressure and at a temperature adaptedvto drive the adhesive and binding material 'throughthe paper so that the adhesive. and binding material not only cements the sheets together but permeates and amalgamates the whole. 1

5. A method of making sound records for talking machines consisting in employing a record surface of thin sheets of non-inflammable. and non-resinous cellulosic material, applying a thin coat of an adhesive and binder comprising asolution 'of a non-inflammable and non-rssinous -cel lulosic materail toa plurality of sheets of porous and absorbent (paper body an heat treating the assembled sheets n n P e sur an at. a emp ratu p ed not. only, to cement the sheets together but to drive the adhesive; and; binding material through, the sheets and,amalgamate the whole together. 1 a

6. A method of making talking machines consisting in employing a record surface ofthin sheets of non-inflammable and non-resinous cellulosic material,

applying a thin coat of an adhesive and binder comprising a solution of a non-inflammable and non-resinouscellulosic material to-a plurality of sheets of porous and absorbent paper to form a laminated inner body and assembling the porous sheets and record surface material together and impressing a matrix upon the latter at a' temperature ada ted to cement the porous sheets and drive the adhesive and binding material through them and amalgamate the whole together.

7 A method of making sound records for talking machines consisting in employing a record surface of thin sheets of non-inflammable and nonresinous cellulosic material, applying athin coat of an adhesive and binder comprising a solution of a, non-inflammable and non-resinous cellulosic material to plurality of sheets of porous and absorbent paper to form a laminated inner .losic' material, thinly coating a plurality of.

sheets of porous and absorbent paper with an adhesive and binder comprising a solu-i tion of a non-mflammable and non-resinous cellulosic 'inaterial so as to leave a porous layer beneath the coating adapted to provide a path for the escape of the, volatile gases, including a plurality of the coated sheets between two outer sheets of record surface material and impressing matrices thereon at a temperature adapted to drive i in out the volatile constituents of the materials employed and to'eause the adhesive-or bind-,

ing material'to unite the sheets together.

9. A method of making a sound record for talking :machines which comprises assembling sheets of a'porous and absorbent paper which have been previously tre'ated with an adhesive and binding material,

applying a layer of cushioning material,

such as rubber, to the outermost of said sheets,- 1fy'mg record surface material in inch) sheet of a record surface material of the formo preformed thin'sheets to said the nature and form specified, a laminated cushioning layer so that the layer lies bebody and a thin cushioning layer (such as tween the porous and absorbent sheets and rubber) between the record surface material 5 the record surface material, and heat-treatand the laminated body. I 15 ing the assembled record blank between In, testimony whereofwe have-signed our matrices at ajhigh temperature adapted to names tothis specification.

' incorporate the whole togetherl s I 10. Aisound record for'talking machines FREDERICK JOHN TURNER. comprising a thin (such as 3/1000thsof an JOHN EDWARD, ERNEST STARGK. 

